Overhead Shoulder Stability and The “Core”
Overhead athletes often suffer injury to the shoulder (glenohumeral) joint secondary to inherent instability. In the Crossfit population, this holds true as well. According to a survey performed in 2014 by Weisenthal and colleagues, the shoulder was the most commonly injured body region amongst 486 CrossFitters. Why is this the case? The answer could lie in the biomechanical requirements of the movement. The performance of the overhead motions require highly skilled movements performed at high velocities. This requires flexibility, muscular strength, coordination, synchronicity and neuromuscular control at the shoulder complex (Wilk et al 2009). A faulty or compensated movement pattern can lead to excessive abnormal accessory gliding, thereby increasing trauma to the joint and causing increased risk for dysfunction and pain (Comerford 2001).
In order to maintain functional stability during limb movement, muscular strength and endurance is required locally around the shoulder girdle. Beyond that, in sports that require a great degree of overhead skill, the “core” or abdominal muscles are instrumental in maintaining proper lumbopelvic stability. The “core” musculature provides a foundation upon which muscles of the upper and lower extremities rely (Willardson 2007).
Clinically speaking, we as physical therapists see this quite often. PIM Presents: Overhead Shoulder Stability from PIM on Vimeo. Jacob from Crossfit Myriad (Redlands, CA) is a crossfitter that came to us hoping to address any muscular imbalances and movement inefficiencies. In our assessment of Jacob’s snatch, we noticed that the left upper extremity was not level as compared to the right extremity at the peak of the snatch. Further evaluation revealed: diminished lateral abdominal activation and reduced scapular upward rotation endurance on the left shoulder girdle. Mobility assessment also revealed lack of end-range shoulder flexion and reduced thoracic extension.
After taking him through a Crossfit-specific corrective exercise program to target his deficits, he is now able to perform his workouts with improved symmetry and even break some of his PRs.
Are your shoulder and core muscles working at their best? If not, you may be at risk for a shoulder injury.
We at Institute for Precision In Movement can help. Visit us for a complimentary